Investigating the structure and function of cupredoxins

Copper is widely used in nature to promote electron transfer in a variety of processes. The metal is usually found as a mononuclear type 1 copper site protected by a protein envelope, which has become known as a cupredoxin fold. In the past few years, the use of protein engineering combined with various spectroscopic and kinetic approaches has provided detailed information about cupredoxins and cupredoxin domains. This review will describe some of the recent advances that have been made, highlighting that there is still a long way to go before we fully appreciate the complexity of biological electron transfer proteins.